Chapter 1: Introduction to Systems Analysis and Design

1. Chapter 1:Introduction to SystemsAnalysis and Design

2. Objectives Understand the fundamental systems development life cycle and its four phases. Understand the evolution of systems development methodologies. Be familiar with the Unified Process and its extensions. Be familiar with the different roles on the project team.

3. Why Should We Care? Would you buy a car that only had a 28% chance of driving off the lot with no problems?

4. Recent Significant IT Failures

5. Systems development life cycle

6. Systems Development Life Cycle

7. SDLC: Planning Why should we build this system? • Project Initiation • Develop a system request • Conduct a feasibility analysis • Project Management • Develop work plan • Staff the project • Control and direct the project

8. SDLC: Analysis What should the system do for us? Where and when will it be used? Develop analysis strategy Gather requirements Develop a system proposal

9. SDLC: Design How will we build the system? Develop a design strategy Design architecture and interfaces Develop databases and file specifications Develop the program design

10. SDLC: Implementation Build the system! • Construct system • Install system • Implement a training plan for the users • Establish a support plan

11. Putting the SDLC Together Each phase consists of steps that lead to specific deliverables The system evolves through gradual refinement Once the system is implemented, it may go back into a planning phase for its next revision, a follow-on system, or maintenance releases

12. Process Product Project Plan System Proposal System Specification New System and Maintenance Plan Planning Analysis Design Implementation Processes and Deliverables

13. Systems development methodologies

14. Systems Development Methodologies • A methodology is a formalized approach to implementing the SDLC • Well-known methodologies include: • Waterfall development • Parallel development • V-model • Rapid application development • Agile development

15. Categories of Methodologies • Structured Design • Waterfall Development • Parallel Development • Rapid Application Development • Phased • Prototyping • Throwaway Prototyping • Agile Development • eXtreme Programming

16. Structured Design 1 Waterfall Development

17. Structured Design 2 Parallel Development

18. Rapid Application Development 1 Phased Development

19. Rapid Application Development 2 System Prototyping

20. Rapid Application Development 3 Throwaway Prototyping

21. Agile Development Extreme Programming

22. Selecting the Right Methodology

23. Object-Oriented Analysis & Design • Attempt to balance emphasis on data and process • Uses Unified Modeling Language (UML) • Characteristics of OOAD: • Use-case Driven • Architecture Centric • Iterative and Incremental

24. The Unified process

25. The Unified Process • A specific methodology that maps out when and how to use the various UML techniques for object-oriented analysis and design • A two-dimensional process consisting of phases and flows • Phases describe how the system evolves over time • Workflows are collections of tasks that occur throughout the lifecycle, but vary in intensity

26. The Unified Process

27. Unified Process Phases Inception Elaboration Construction Transition

28. Engineering Workflows Business modeling Requirements Analysis Design Implementation Testing Deployment

29. Supporting Workflows Project management Configuration and change management Environment Operations and support* Infrastructure management* * Part of the enhanced unified process

30. The unified modeling language

31. Unified Modeling Language • Provides a common vocabulary of object-oriented terms and diagramming techniques rich enough to model any systems development project from analysis through implementation • Version 2.0 has 14 diagrams in 2major groups: • Structure diagrams • Behavior diagrams

32. UML Structure Diagrams • Represent the data and static relationships in an information system • Class • Object • Package • Deployment • Component • Composite structure

33. UML Behavior Diagrams • Depict the dynamic relationships among the instances or objects that represent the business information system • Activity • Sequence • Communication • Interaction overview • Timing • Behavior state machine • Protocol state machine, • Use-case diagrams

34. Project team roles and skills

35. Project Team Skills • Project team members are change agents who find ways to improve their organization • A broad range of skills is required, including • Technical • Business • Analytical • Interpersonal • Management • ethical

36. Project Team Roles

37. Summary All systems development projects follow essentially the same process, called the system development life cycle (SDLC) System development methodologies are formalized approaches to implementing SDLCs Object-Oriented Systems Analysis and Design (OOSAD) uses a use-case-driven, architecture-centric, iterative, and incremental information systems development approach

38. Summary The Unified Process is a two-dimensional systems development process described with a set of phases and workflows The Unified Modeling Language, or UML, is a standard set of diagramming techniques The project team needs a variety of skills